In recent years, in a manufacturing process of semiconductor devices, a technique has been developed for simplifying the manufacturing process of semiconductor devices by testing semiconductor devices in a wafer state. According to such a technique, a plurality of semiconductor devices formed on a single wafer are subjected to various semiconductor tests in a wafer state and also being subjected to packaging. Then, the semiconductor devices packaged in a wafer state is separated from each other. According to such a technique, the semiconductor devices can be managed on an individual lot basis. Additionally, a cost spent on the packaging of a defective semiconductor device can be eliminated.
Many semiconductor devices are formed on a single wafer in an aligned state. Electrodes such as power supply electrodes or an input and output signal electrodes are formed on each of the semiconductor devices. Therefore, in order to apply a test to the semiconductor devices while driving them, an electrical contact must be made with each of the semiconductor devices. That is, it is necessary to make a contact with the electrodes provided on each semiconductor device.
The number of the electrodes formed on one semiconductor device may be several hundreds when it is large. Moreover, more than hundreds of semiconductor devices are formed in one wafer. Therefore, in order to make a contact with an entire wafer simultaneously, the contact must be made with as many as several hundreds of thousands of electrodes at one time. Generally, in order to make a contact with electrodes of a semiconductor device, a contactor having contacts, which individually contact with respective electrodes of the semiconductor device, is used. Therefore, in order to make a contact with semiconductor devices in a wafer state simultaneously, it is necessary to form contacts of the same number as the number of the electrodes on the wafer on the contactor. That is, in order to test a wafer having several hundreds of thousands of electrodes, several hundreds of thousands of electrodes must be formed on the contactor.
Thus, in order to make a contact of such many contacts simultaneously, an extremely large pressure is needed. For example, if the contact pressure necessary for one contact point is several grams, a pressure of several hundreds kilograms must be applied for a contactor which contacts an entire wafer.
Moreover, when as many as several hundreds of thousands of contacts are formed on the contactor, pattern wirings must be formed on the contactor so as to electrically connect the contacts to external terminals. However, since a large area is needed for providing the pattern wirings, there is a problem in that it is difficult to form such many pattern wirings on one contactor.